Effects of Sodium Carbonate on Striga hermonthica Del. Infestation and Agro-morphological Parameters of Sorghum bicolor (L.) Moench in the Sudano-Sahelian Zone of Cameroun

Sorghum bicolor is the main food widely used to feed millions of people in Central and West Africa. Sorghum production in Sub-Saharan Africa is limited by biotic factors including the parasitic witchweed Striga hermonthica. In Northern Cameroon chemical and organic fertilizers, biological methods and cultivation practices were used by farmers to control Striga hermonthica in field. Some farmers spread sodium carbonate salt (locally named natron or kilbou) in high rates in fields to reduce parasite infestation but in high rate. This salt plays an important role in soil pH buffering. This study was conducted to evaluate effects of different rates of natron on striga emergence and on agro-morphological parameters of sorghum using a susceptible genotype GD-MP04. Field experiments have been conducted from 2017 to 2018 at Touboro, Mayo-Rey Division in the North Region located between longitude 13°34’; 12°07’ East and latitude 7°21’; 15°01’North. The experimental design was a complete randomized bloc with pots (11 m × 11 m) filled with soil naturally infected by striga seeds and different rates of sodium carbonate (0 g, 2 g, 4 g, 6 g, 8 g, 10 g and 12 g per 5 dm3 of soil) were employed. The numbers of emerged striga and sorghum parameters were evaluated. Results showed that striga-infestation and agro-morphological parameters of sorghum varied significantly (p <0.05) with rates of sodium carbonate. The mean number of emerged striga plants per pot varied from 0.08 in pot of 2 g of salt to 5.4 in the control. The number of sorghum leaves per plant, stem diameter, sorghum height, panicle weight and sorghum kernel yield varied significantly (p <0.05) with natron application rate. The application of 2 g of sodium carbonate per pot was the optimal rate to control Striga hermonthica and improve the main agro-morphological parameters of sorghum with 78.27% increase in g of kernel yield and simultaneously inhibited striga infestation by 98.62%. Application of 2 g of sodium carbonate in area naturally infested by striga for improving sorghum yield is required.